1. Marcus - He's, well, he's Marcus. I even like him when he's being goofy, and I actually feel Last Crusade did him a huge favor making him part of the action.
2. Mola Ram - Love those crazy eyes, and that laugh. He's also the only main villain in the original films to not be afraid to get his hands dirty. Compare this to Belloq, who, while cool, relies too much on hired help.
3. Tough Sergeant - You knew this guy was gonna be on my list. He's my avatar for Shiva's sake! Not only was he smart enough to climb over the truck....he also isntantly deduced in a nanosecond where his last man had shot Indy. That's genius.

Others:

Henry Jones - "These people are trying to kill us!" "I know, Dad!" "....it's a new experience for me." He's everybody's grumpy dad rolled into one immensely likable character. Plus, he also knows what he's talking about most of the time.Sallah - If I need to explain why I like Sallah, then Sallah wouldn't be Sallah.Gobler - He said little and was an awful driver, but his utter lack of impact on the plot despite several efforts to involve himself makes me love him. You gotta love him for at least trying.Vogel - "This is how we say goodbye in Germany." 'Nuff said.Lao Che - Gotta love that tuxedo, and that facial hair. Not to mention the fact he gets everything he wants. The diamond, Nurhachi's ashes, and revenge on Indy for killing his son - by sending him on a collision course with the Thuggee.